Brake Pad Change...Unhappy :X
10-08-09, 03:26 PM
#46
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Would like to throw my 2 cents in on your brake problems. A brake squeel is caused by a harmonic vibration. Cause in most cases is replacing pads and not turning the brake rotors. As pads wear in most cases, a small amount of uneven wear occurs on the rotor surface. With new pads being perfectly flat, put on an uneven rotor surface the pad makes contact only with the highest points on the rotor. This leads to a very small contact point in several places and causes overheating of the friction material in those places, or glazing. Turning rotors does 2 things. Removes any lateral run out or warpage, and gives the new pads a smooth even surface to bed into. IS-F rotors have a new thickness of 1.180 and discard thickness of 1.110. Most rotor surfaces can be cleaned up by removing .005 to .010 of material per side. Given normal wear these rotors should be thick enough to be turned 1 and maybe 2 times.
When the brake pads are installed, use caliper grease between the shims and pads, all points where the pad backing contacts the caliper, and a small amount can even be placed where the pistons contact the pad. Not sure what the oem friction material is, but as a rule ceramic pads should not make any noise, and reduce dusting. Hope this helps.
One other thing. When seating the caliper pistons back into the bores, it is best to open the bleeder and let the fluid escape there instead of pushing it back thru the system into the master cylinder.
When the brake pads are installed, use caliper grease between the shims and pads, all points where the pad backing contacts the caliper, and a small amount can even be placed where the pistons contact the pad. Not sure what the oem friction material is, but as a rule ceramic pads should not make any noise, and reduce dusting. Hope this helps.
One other thing. When seating the caliper pistons back into the bores, it is best to open the bleeder and let the fluid escape there instead of pushing it back thru the system into the master cylinder.
10-08-09, 03:44 PM
#49
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You've done some brakes in your time it sounds like....can you tell me why there is a 3/8" rust ring around both of my front rotors nearest the hub and the OEM pads did not leave this ring?...that means to me that there is no contact at all there, none...the rest of the rotor out from the hub has these little wear cocentric circles...if the pads are the exact same size as OEM's, what's going on in that last 3/8" closest to the hub? I can't imagine it making no contact at all???? It's like the piston is pushing only on the top part of the pad...is that possible? I don't know brakes so bear with me here..
I do this for a living and have done a few brake jobs in my time.....like 35 years worth. Every situation is a bit different, but there is alway a solution to every problem.
10-08-09, 08:43 PM
#51
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BB/F is correct. most pads footprint does not extend all the way to the center edge of the rotor surface. It is important to compare the new pads to the old pads regarding the surface of the pad. Some may vary slightly and makes turning or replacing the rotors even more important.
The Aftermarket pad reaches the center edge of the rotor line, but the pad itself is not making contacting in that area during braking.
Joe Z
10-09-09, 06:11 AM
#52
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Looking at that rotor, I see a lip on the outside edge of the rotor. It doesnt look like the rotor was turned before installing the new pads. If it wasnt, it doesnt surprise me that there is not even contact between the face of the pad and the rotor.
10-09-09, 12:22 PM
#53
Just a side note, do you guys know there is actually a TSB about the factory brake pads?
It's one of those "you have to complain about it" in order for it to be dealt with and for them to acknowledge the TSB. A lot like the alignment TSB....
TSB is in regards to brake noise and squeal. Pads are replaced with a different pad that has a changed leading edge.
Just thought you all should know. My F had the pads replaced by the dealer.
It's one of those "you have to complain about it" in order for it to be dealt with and for them to acknowledge the TSB. A lot like the alignment TSB....
TSB is in regards to brake noise and squeal. Pads are replaced with a different pad that has a changed leading edge.
Just thought you all should know. My F had the pads replaced by the dealer.
Are the new pads dusty? Or they improved? Give us more here...
Hey mondo, I've been discussing this problem directly with Hawk, there have been emails back and forth, but after providing details as well as pictures it seems like they don't care, last time I heard from them was a full week ago.
I know the pads are the same size and shape as OEM, but for some reason they don't make contact completely. My guess is that they flex at the lower area, maybe too soft? Three things though: they're quiet, dust is minimal, and they have great stopping power, BUT I hate that rust ring on my rotors!!!
I think you should complain to Hawk, if you want I can PM you the contact info.
I know the pads are the same size and shape as OEM, but for some reason they don't make contact completely. My guess is that they flex at the lower area, maybe too soft? Three things though: they're quiet, dust is minimal, and they have great stopping power, BUT I hate that rust ring on my rotors!!!
I think you should complain to Hawk, if you want I can PM you the contact info.
On another note, I have that same ring of rust around my rotor as well now...I'll take pics later.
10-09-09, 01:04 PM
#54
FAILED TO MENTION:
I used a powerwasher/self car wash last weekend and sprayed down my wheels/rotors pretty well and since then noticed the squeek go away. (KNOCK ON WOOD PLEASE DON'T LET IT COME BACK!!!) Maybe it loosed up some of that old caked on dust?
Chime in....
I used a powerwasher/self car wash last weekend and sprayed down my wheels/rotors pretty well and since then noticed the squeek go away. (KNOCK ON WOOD PLEASE DON'T LET IT COME BACK!!!) Maybe it loosed up some of that old caked on dust?
Chime in....
10-09-09, 01:40 PM
#56
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I worked at a machine shop for along time and we would turn drums and rotors for walk in customers. Over time, I noticed that the manufacturers started making the rotors thinner so you could turn them maybe once depending how bad they were worn. Pretty smart. Make it so you have to pay for new rotors anytime you need brakes. Makes them money.
10-09-09, 02:12 PM
#57
They should be machined so that they are completely true before installing new pads. Wear and heat will distort the rotor over time so if you dont turn them before installing new pads, you dont have a true surface to figure out if something is wrong with the pad. I've heard that the stock rotors cant be turned because it puts them out of spec so you have to buy new ones. But there is a spec and if its still within spec, they can be turned and still usable.
I worked at a machine shop for along time and we would turn drums and rotors for walk in customers. Over time, I noticed that the manufacturers started making the rotors thinner so you could turn them maybe once depending how bad they were worn. Pretty smart. Make it so you have to pay for new rotors anytime you need brakes. Makes them money.
I worked at a machine shop for along time and we would turn drums and rotors for walk in customers. Over time, I noticed that the manufacturers started making the rotors thinner so you could turn them maybe once depending how bad they were worn. Pretty smart. Make it so you have to pay for new rotors anytime you need brakes. Makes them money.
That might be the reason why I am getting the squeel? However, not sure you read my post but since powerwashing them it hasn't happened. *CROSSES FINGERS*
10-09-09, 02:45 PM
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Man, we can't get definite anything....
- is there a TSB on OEM brake pads or not?
- are the hawk pads defective or not?
- was the install process done wrong by not turning rotors or not? (well Lexus says no or you can't turn them, others say you can, and should)
- what is causing the rust ring? the pads or the install?
- do you flush brake fluid or not when you change pads? I added this one.
I am out $400 and annoyed (not at anyone on this thread)...within the very first week of my pads being changed (first car wash)...I noticed that damn rust ring... contacted my installing dealer , took and sent pics, expressed my concern about the pads or the install....was assured they were of utmost quality and install done correctly. Well, my rear rotors have no rust ring, but my fronts do. I'm letting it go...lesson learned and in the grand scheme it wasn't that expensive of a lesson. Thx everyone for the info...I learned a few things...I think.
- is there a TSB on OEM brake pads or not?
- are the hawk pads defective or not?
- was the install process done wrong by not turning rotors or not? (well Lexus says no or you can't turn them, others say you can, and should)
- what is causing the rust ring? the pads or the install?
- do you flush brake fluid or not when you change pads? I added this one.
I am out $400 and annoyed (not at anyone on this thread)...within the very first week of my pads being changed (first car wash)...I noticed that damn rust ring... contacted my installing dealer , took and sent pics, expressed my concern about the pads or the install....was assured they were of utmost quality and install done correctly. Well, my rear rotors have no rust ring, but my fronts do. I'm letting it go...lesson learned and in the grand scheme it wasn't that expensive of a lesson. Thx everyone for the info...I learned a few things...I think.
10-09-09, 04:22 PM
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Man, we can't get definite anything....
- is there a TSB on OEM brake pads or not? Dont know
- are the hawk pads defective or not? Dont know. My guess is the pads were fine. But since the rotors werent turned or new you wouldnt be able to troubleshoot unless you started with a fresh pad and rotor and determined if the problem still showed up
- was the install process done wrong by not turning rotors or not? (well Lexus says no or you can't turn them, others say you can, and should) A proper brake job involves fresh pads and turned/or new rotors. The important thing here is you have two perfectly flat surfaces for proper bedding. You get the true surface on the rotor by turning it or installing a new rotor. You can install pads without turning the rotors but your results may vary.
- what is causing the rust ring? the pads or the install? The ring is caused by the pad not touching the rotor. No surprise if the rotor wasnt turned
- do you flush brake fluid or not when you change pads? I added this one. Up to you
I am out $400 and annoyed (not at anyone on this thread)...within the very first week of my pads being changed (first car wash)...I noticed that damn rust ring... contacted my installing dealer , took and sent pics, expressed my concern about the pads or the install....was assured they were of utmost quality and install done correctly. Well, my rear rotors have no rust ring, but my fronts do. I'm letting it go...lesson learned and in the grand scheme it wasn't that expensive of a lesson. Thx everyone for the info...I learned a few things...I think.
- is there a TSB on OEM brake pads or not? Dont know
- are the hawk pads defective or not? Dont know. My guess is the pads were fine. But since the rotors werent turned or new you wouldnt be able to troubleshoot unless you started with a fresh pad and rotor and determined if the problem still showed up
- was the install process done wrong by not turning rotors or not? (well Lexus says no or you can't turn them, others say you can, and should) A proper brake job involves fresh pads and turned/or new rotors. The important thing here is you have two perfectly flat surfaces for proper bedding. You get the true surface on the rotor by turning it or installing a new rotor. You can install pads without turning the rotors but your results may vary.
- what is causing the rust ring? the pads or the install? The ring is caused by the pad not touching the rotor. No surprise if the rotor wasnt turned
- do you flush brake fluid or not when you change pads? I added this one. Up to you
I am out $400 and annoyed (not at anyone on this thread)...within the very first week of my pads being changed (first car wash)...I noticed that damn rust ring... contacted my installing dealer , took and sent pics, expressed my concern about the pads or the install....was assured they were of utmost quality and install done correctly. Well, my rear rotors have no rust ring, but my fronts do. I'm letting it go...lesson learned and in the grand scheme it wasn't that expensive of a lesson. Thx everyone for the info...I learned a few things...I think.
10-10-09, 08:56 AM
#60
When I took my IS-F to the dealer (before doing the brake job) they checked both front and rear brakes, they said that rears were fine at 7mm or 8mm (don't remember exactly), but fronts were at 3mm and I should change pads soon. They inspected the front rotors and said that in many cases the rotors need to be replaced, but they may cut them if it's still possible. In my case they said that rotors were in great shape and I had to worry only about pads, rotors were fine as is. Of course I followed their advise and replace the pads only, but I went with Hawk ceramics trying to avoir brake dust. Again my only complain is that bad looking rust ring.